Peter Bentley believes we may one day see an America’s Cup Class yacht that is capable of breaking through the 50-knot barrier, now that teams have taken the training wheels off.

The technical rules adviser for Artemis Racing is also a senior member of the design team tasked with getting the most out of the AC50s being used in the 35th America’s Cup.

And while the six teams have regularly reached the high thirties and have occasionally sailed into the forties, going faster still is not yet within reach.

That does not mean it will not be possible, but increased speed comes with increased stability problems, which Emirates Team New Zealand discovered to their cost on Tuesday.

“We could produce a set of foils for these yachts relatively easily, and I stress the word ‘relatively’, to break through 50 knots in a straight line,” Bentley said. “Whether we can actually get the yachts around the course with those foils is an altogether different question.”

As this newest incarnation of the America’s Cup has shown, technological advances are being made all the time, primarily as the teams learn more and more about the boats.

The dry lap achieved by Emirates Team New Zealand last week during the Louis Vuitton America’s Cup Qualifiers broke down another barrier in terms of engineering, and Bentley believes there are plenty more to fall.

For Bentley, the next task is all about refining machines that are the future of the sport.

“We’ve had an America’s Cup of learning to sail these boats, and learning what they’re about, and really we’re going from — if it was a bicycle — having the training wheels on, to taking the training wheels off,” Bentley said.

“We’re sailing those boats pretty fast; it’s now about understanding, if we take the cycling analogy, what gear to be in, what pressure to have the tyres, some of the much smaller, finer details about to really refine the boat.”

Of course, Bentley will be the first to admit there are changes coming that people will not have expected to see.

“As with any branch of technical endeavour, just when you thought you knew everything, you find out something new every day,” Bentley said. “That’s what makes it fascinating.”

At the heart of those advances is the need to balance speed and stability, challenges that a sport that is billing itself as the “Formula One on Water” is facing every day. And where the friction between tyre and road is central to the car version, here the relationship between foil and water is key.

“How fast you can go is fundamentally limited by cavitation, which is where, in very simple terms, the water around the daggerboard and rudder boils,” Bentley said.

“Water can boil at any temperature depending on the pressure, and the way the daggerboard works is that there is a high-pressure side and low-pressure side, and if the pressure gets low enough on one side, the water boils and you get a big bubble of air around the foil and that slows you down.

“Cavitation is the limit on speed. The problem there is that the foil, which is good at high cavitation speed, has poor stability and poor control.”

To adapt to these new technological challenges, teams have been using the expertise of designers and engineers from the world of motorsport, with Land Rover BAR a prime example. Martin Whitmash, a former chief executive of McLaren Racing, Adrian Newey, of Red Bull, and Richard Hopkirk, an engineer who helped to turn Lewis Hamilton into a world champion, all brought on board.

Artemis have got into the act as well, bringing Martini Racing and their relationship with Williams into the mix. At a get-together at Artemis’s base in Dockyard yesterday, Bentley and Giles Ritchie, the Global F1 Sponsorship Manager for Martini Racing, discussed the similarities between the sports.

For Bentley and his team, the issue of speed versus stability is at the core of what they are trying to achieve on the water, as they chase down SoftBank Team Japan in their semi-final of the Louis Vuitton America’s Cup Challenger Play-offs.

According to Bentley, the balancing act between the two is a constant trade-off, mostly involving the position of the daggerboard, rudder and foils.

“At its very simplest, the boat is fastest when the horizontal part [of the daggerboard] is roughly parallel with the surface of the water, but it’s least stable,” Bentley said. “When the tip is pointing uphill, the boat achieves some natural stability on its own, but then you are giving away speed.

“You can also design the daggerboard in a way that makes it more or less stable, and that also trades off against the speed.

“Fundamentally, the better the quality of your control system, your hydraulics and electronics, the more precisely you can drive the daggerboard and get it exactly where you want it, the more you can sail with an unstable and therefore faster daggerboard.”